/*
 * SNMP Package
 *
 * Copyright (C) 2002, Jonathan Sevy <jsevy@mcs.drexel.edu>
 *
 * This is free software. Redistribution and use in source and binary forms, with
 * or without modification, are permitted provided that the following conditions
 * are met:
 *
 *  1. Redistributions of source code must retain the above copyright notice, this
 *     list of conditions and the following disclaimer.
 *  2. Redistributions in binary form must reproduce the above copyright notice,
 *     this list of conditions and the following disclaimer in the documentation 
 *     and/or other materials provided with the distribution.
 *  3. The name of the author may not be used to endorse or promote products 
 *     derived from this software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR IMPLIED 
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF 
 * MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO 
 * EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT
 * OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 
 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 */

package snmp;




import java.math.*;


/** Defines a 32-bit gauge, whose value "pegs" at the maximum if initialized with a larger
* value. For an indicator which wraps when it reaches its maximum value, use SNMPCounter32; 
* for a counter with a wider range, use SNMPCounter64.
* @see snmp.SNMPCounter32
* @see snmp.SNMPCounter64
*/


public class SNMPGauge32 extends SNMPInteger
{
	// maximum value is 2^32 - 1 (hack w/ 4*107...)
	private static BigInteger maxValue = new BigInteger("4294967295");
	
	/** Initialize value to 0.
	*/
	
	public SNMPGauge32()
	{
		this(0);	// initialize value to 0
	}
	
	
	public SNMPGauge32(long newValue)
	{
		tag = SNMPBERCodec.SNMPGAUGE32;
		
		value = new BigInteger(new Long(newValue).toString());
		
		// peg if value > maxValue
		value = value.min(maxValue);
	}
	
	
	
	
	/** Used to initialize from the BER encoding, usually received in a response from 
	* an SNMP device responding to an SNMPGetRequest.
	* @throws SNMPBadValueException Indicates an invalid BER encoding supplied. Shouldn't
	* occur in normal operation, i.e., when valid responses are received from devices.
	*/
	
	protected SNMPGauge32(byte[] enc)
		throws SNMPBadValueException
	{
		tag = SNMPBERCodec.SNMPGAUGE32;
		
		extractValueFromBEREncoding(enc);
		
		// peg if value > maxValue
		value = value.min(maxValue);
	}
	
	
	
	
	/** Used to set the value with an instance of java.lang.Integer or
	* java.lang.BigInteger. The value of the constructed SNMPGauge32 object is the
	* supplied value or 2^32, whichever is less.
	* @throws SNMPBadValueException Indicates an incorrect object type supplied.
	*/
	
	public void setValue(Object newValue)
		throws SNMPBadValueException
	{
		// plateau when value hits maxValue
		if (newValue instanceof BigInteger)
		{
			value = (BigInteger)newValue;
			value = value.min(maxValue);
		}
		else if (newValue instanceof Integer)
		{
			value = value = new BigInteger(newValue.toString());
			value = value.min(maxValue);
		}
		else if (newValue instanceof String)
		{
			value = value = new BigInteger((String)newValue);
			value = value.min(maxValue);
		}
		else
			throw new SNMPBadValueException(" Gauge32: bad object supplied to set value ");
	}
	
	
}